Interaction between β blockers and epinephrine on hemodynamics of spontaneously hypertensive rats

研究非选择性β肾上腺素能阻滞剂与肾上腺素相互作用对自发性高血压大鼠（SHR）和Wistar Kyoto大鼠（WKY）血流动力学的影响。（研究1）：给予非选择性β受体阻滞剂、品多洛尔和2%利多卡因（含1:8万肾上腺素）腹腔注射清醒SHR和WKY，采用光体积脉搏仪尾袖带法测量血压和心率。肾上腺素未引起品多洛预处理后WKY的明显血流动力学改变。另一方面，SHR患者血压明显升高。由此可见，肾上腺素对周围血管床的作用在品多洛尔存在时被夸大了。在另一项研究中，给SHR和WKY腹腔注射苯肾上腺素。SHR组血压升高比WKY组明显。结果表明，SHR对刺激剂的敏感性高于WKY。（研究2）：全麻下静脉注射异丙酚、非选择性β受体阻滞剂、普萘洛尔。然后连续静脉注射肾上腺素至SHR和WKY。通过股动脉侵入性测量血压和心率。我们发现在SHR和WKY中，肾上腺素联合普萘洛尔诱导血压显著升高。由此可见，在普萘洛尔的存在下，肾上腺素对周围血管床的作用被夸大了。就病理特征而言，SHR更容易被异丙酚扩张血管。这可能是SHR组和WKY组血压没有差异的原因。

We investigated the effects of the interaction between nonselective β adrenergic blocking agents and epinephrine on the hemodynamics in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY).(Study 1) : Nonselective β blocker, pindolol, and 2% lidocaine containing 1:80,000 epinephrine were administered to conscious SHR and WKY intraperitoneally Blood pressures and heart rate were measured by the photoplethysmografic tail cuff method. Epinephrine did not cause significant hemodynamic changes in WKY after the pindolol pretreatment. On the other hand, blood pressure increased significantly in SHR. From these observation, it was suggest that a effects of epinephrine on peripheral vascular bed was exaggerated in the presence of pindolol.In an additional study, fenylephrine was administered to SHR and WKY intraperitoneally. There was more marked increase in blood pressure in SHR than WKY. This result showed that SHR was more sensitive to a stimulator than WKY.(Study 2) : Under general anesthesia with propofol, nonselective β blocker, ploplanolol was injected intravenous. Then epinephrine was injected intravenous continuously to SHR and WKY. Blood pressure and heart rate were measured invasively through the femoral artery. We found that in both SHR and WKY, epinephrine in combination with proplanolol induced remarkable increase in blood pressure. From these observation, it was suggest that a effects of epinephrine on peripheral vascular bed was exaggerated in the presence of proplanolol. For the pathologic features, SHR is more prone to vasodilation by propofol. This might be the reason why there were no differences in bloodpressure between SHR and WKY.